Background: Chromoblastomycosis is defined as mycosis of the skin and subcutaneous cellular tissue. It belongs to the group of tropical verrucous syndrome diseases. It is mainly caused by dematiaceous fungi such as F. pedrosoi and C. carrionii. Normally, it occurs after a penetrating trauma to the skin with plant objects, and that's why it is more common in farmers or peasants in the tropic. Different complications have been described with malignant transformation, mainly squamous cell carcinoma being the most serious complication [1][2]. we present the case of a patient diagnosed with chronic chromoblastomycosis and associated squamous cell carcinoma This is the case of a 70-year-old male patient, from Mosquera Cundinamarca in Colombia, with diagnosis of Chromoblastomycosis since 2016 made by skin biopsy, which reported a pseudoepitheliomatous and irregular epidermal hyperplasia, lymphohistioplasmacytic infiltrate and presence of pigmented yeasts evident with hematoxylin eosin staining. On physician examination Yellowish brown tumor plaque, with a warty surface with black dots located on the back of the hand with extension to the proximal third of the forearm He received treatment with Terbinafine 500 mg every 12 hours and Itraconazole 200 mg every 12 hours for 1 year without obtaining clinical improvement, hence left transhumeral amputation was performed with evidence of well-differentiated squamous cell carcinoma, keratinizing and infiltrating soft tissues and in contact with bone. Three months after surgical management, he presented new lesions in the stump suggestive of chromoblastomycosis, for which extension of the stump amputation was indicated Nummular erythematous and scaly plaques with black dots on the surface in the proximal third of the left arm Methods: Descriptive observational case report type. Results: In cases of long-term infection caused mainly by Fonsecaea pedrosoi, poor response to treatment, extensive lesions and associated ulcerations predispose to malignant transformation to melanoma or squamous cell carcinoma, these being the most serious risk factors for malignancy bad prognosis [1]. Conclusions: Chromoblastomycosis is a chronic deep mycosis, which can present different complications. Therefore, taking these into account will help provide a timely diagnosis, taking into account these possible association [1][2]. References[1]Rojas OC, (2015), Chromoblastomycosis by Cladophialophora carrionii Associated with Squamous Cell Carcinoma and Review of Published Reports.[2]Azevedo CMPS, (2015),. Squamous Cell Carcinoma Derived From Chronic Chromoblastomycosis in Brazil. Clinical Infectious Diseases